Cryptology ePrint Archive: Report 2007/260

An Efficient One-move Nominative Signature Scheme

Dennis Y. W. Liu and Qiong Huang and Duncan S. Wong

Abstract: A signer in a Nominative Signature (NS) scheme can arbitrarily choose a nominee, then jointly generate a signature in such a way that the signature can only be verified with the nominee's consent. NS is
particularly useful in user certification systems. Currently, the only secure NS scheme available requires multi-round communications between the nominator and the nominee during signature generation. This implies that an NS-based user certification system requires a certification issuer to interact with a user using a complicated multi-round protocol for certificate issuance. It remains an open problem to construct an efficient and non-interactive NS scheme. In this paper, we solve this problem by proposing the first efficient one-move (i.e. non-interactive) NS scheme. In addition, we propose an enhanced security requirement called Strong Invisibility, and prove that our scheme satisfies this strong security requirement.